The present invention relates to a thermostatic gas valve for regulating the combustion in a domestic heating appliance or cooker using a diaphragm valve for regulating the maximum gas pressure delivered at the valve inlet.
Thermostatic gas valves are already known for the delivery of a modulated main gas flow to a main burner and of a pilot gas flow to a pilot ignition burner, such as that disclosed in ES-2145652 (No. 96001716)/U.S. Pat. No. 5,816,490, wherein the valve body comprises a plurality of internal gas distribution chambers, a gas inlet duct from a supply, a main flow outlet duct, and a pilot flow outlet duct. An electromagnetic safety valve held open by a thermocouple is built in adjacent to the inlet duct and it controls the incoming gas to the valve, which is distributed in a main flow modulated by a thermostatic bellows valve, and in a pilot flow transmitted to an outlet duct connectable to the pilot burner. The internal gas distribution chambers are sealed to the exterior by flat covers screwed on to different surfaces of the body.
An arrangement is also known of a maximum gas pressure regulator in a thermostatic valve which delivers a modulated flow to a main burner and a pilot flow to a pilot burner, as the one disclosed in U.S. Pat. No. 3,666,173. The pressure regulator is connected downstream between the safety valve outlet and the pilot flow outlet duct, and is also connected to a thermostatic valve which receives a gas pressure to modulate a main gas flow.
The object of the invention is a thermostatic gas valve for the delivery of a modulated gas flow to a main burner, with a maximum inlet pressure regulating device built into the body of the thermostatic valve and connected directly at the thermostatic valve inlet duct.
The pressure regulator device comprises a cylindrical body with an internal enclosure divided by a diaphragm type valve. The diaphragm defines a gas chamber stabilised at a nominal pressure value downstream from the valve. The pressure regulator device is fitted into the thermostatic valve from the outside, in a housing in the valve body wherein it is inserted, connected directly at the thermostatic valve inlet duct. The upstream and downstream gas passage conduits directed to and from the regulator device are formed in the body of the thermostatic valve, without altering the construction of the plurality of the thermostatic valve internal gas distribution chambers.